Excessive dynamic airway collapse (EDAC) and tracheobronchomalacia (TBM) occur due to abnormal weakening of the walls of the central airways leading to central airway collapse on expiration. This collapse is responsible for breathlessness, cough or syncope. In adults, this weakening can be idiopathic (Mounier-Khun syndrome), secondary to respiratory diseases such as chronic obstructive pulmonary disease (COPD), secondary to systemic diseases such as relapsing polychondritis (RP) or secondary to invasive ventilation or trauma. The incidence of EDAC and TBM varies from 12% in all patients undergoing bronchoscopy to 44% in patients with chronic bronchitis undergoing bronchoscopy. Gold standard for the diagnosis of EDAC and TBM is bronchoscopy which identifies and quantifies the narrowing of the airway. Non-invasive technique such as inspiratory and expiratory chest computed-tomography (CT) can also be used to diagnose EDAC / TBM.